1. Field of the Invention
The present invention generally relates to an automobile body structure, and more particularly, to an automobile rear body structure.
2. Description of the Prior Art
Conventionally, an automobile rear body structure is generally comprised of a pair of spaced rear side frames each extending in a direction longitudinally of a vehicle body and a cross member extending transversely between the rear side frames and having opposite ends welded or otherwise secured to the rear side frames at the location of a rear wheel housing. To this cross member are generally secured suspension support members for carrying respective rear suspension systems, a differential unit support member for carrying a differential unit, and the like.
Accordingly, joints between the rear side frames and the cross member are required to be rigidified and strengthened. Japanese Utility Model Publication (examined) No. 62-35643 discloses one example of the structure of the joints.
A rear bumper is rigidly secured to the rear ends of the rear side frames. In the event of a rear-end collision, an impact load imposed upon the rear bumper is transmitted to the rear side frames and the impact energy is effectively absorbed by compressive buckling of the bumper and bending deformation of the rear side frames, thereby minimizing damage to a passenger compartment.
Since the joints between the rear side frames and the cross member have substantial rigidity and strength, the rear side frames are likely to be bent at locations behind the respective joints.
In general, a rear floor panel constituting a rear floor of the vehicle body is also secured to the rear side frames and a fuel tank is disposed on a lower surface of the rear floor panel behind the cross member.
Accordingly, if the rear side frames are bent or deformed at the locations behind the joints thereof with the cross member in the event of a rear-end collision, it is very likely that the fuel tank would be damaged. Such an arrangement, therefore, includes room for improvement of safety.